1. Field of the Invention
The present invention relates generally to storage systems, such as unified storage systems.
2. Description of Related Art
Unified storage is a concept whereby multiple different types of storage technologies can be implemented using a single hardware platform. As the hardware components of storage systems have become more standardized, such as through the use of standard CPUs, standard memory modules, etc., different types of storage control software are able to run on the same storage hardware platform. A primary advantage of a unified storage system is a reduction in hardware requirements, so that a single hardware system can be used for a variety of storage uses. A unified storage system should, at a minimum, simultaneously enable storage of file-type data and storage of the block-based input/output (I/O) operations produced by enterprise application programs. Instead of having to provide separate storage platforms, such as a network attached storage (NAS) system for file-based storage and a RAID disk array for block-based storage, a unified storage system should be able to be used for either function independently, while also being able to combine both functions for simultaneous use. Further, a unified storage system should also be able to incorporate and perform more advanced storage technologies, such as CAS (Content Addressable Storage), VTL (Virtual Tape Library), VDL (Virtual Disk Library), OOS (Object-Oriented Storage), and so on.
Current Solutions and Their Problems
Most conventional storage systems are still single control type systems, which means they are either block based storage systems, NAS systems, CAS systems, VTL systems, VDL systems, OOS systems, etc. However, some vendors have begun to provide multiple control systems. These multiple control systems are typically a NAS platform that is modified to add block-storage support, although some are a combination of FC-SAN (Fibre Channel-Storage Area Network) and IP-SAN (Internet Protocol-Storage Area Network) (iSCSI) block-based storage, or a combination of NAS and iSCSI (Internet Small Computer System Interface).
However, the prior art systems are all static systems in that they are specifically configured to handle one or two predetermined protocols, rather than being able to dynamically change to accommodate different protocols. Thus, the prior art systems suffer from an inability to automatically and dynamically install and run the different forms of storage control software on other hardware platforms in order to dynamically and flexibly change the tasks that the system is able to carry out. For example some prior art unified storage systems are able to provide block-based (FC and iSCSI) and file system control simultaneously. However, the controls for these systems may be based in the common OS and File System layer running on one hardware platform. Therefore, even when providing block-based functionality, the operations have to be handled by the file system layer, which creates undesirable overhead, and thereby decreases the efficiency of the block-based storage. Also, such a setup makes it difficult to change between block and file configurations after starting up the system. Moreover, the system is not able to automatically and dynamically change its configuration based on the system load so as to better balance the load.